People eat what they like, but that food may not be entirely healthy all the time. To prevent such unhealthy eating, different countries have been recommending health-friendly diets for their citizens, and now a new study published in PNAS (Proceedings of the National Academy of Sciences) has stressed more than ever on these government-endorsed diet charts.

The reason is these foods not only keep you healthy but are also good for the environment. Growing or raising, processing, and transporting food to households affects environment with 20-30% global greenhouse gas emissions, use of land, and polluted waterways.

A group of Dutch researchers who undertook the study suggests tweaking diets and following government recommendations could actually help in cutting greenhouse gas emissions in some — if not all — countries.

According to a report in National Public Radio, the researchers created a database of 37 high-, medium-, and low-income nations, and compared the environmental impact of what they've been eating on average with what they should it.

The results revealed 28 high-income countries could be a major contributor toward reducing environmental stress. By following what their respective governments suggest and eating less of meat, poultry and eggs, people could bring greenhouse gas emissions down by 13-25%, free up 6-17% land for nature, and reduce waterway pollution by 10-21%.

"At least in high-income countries, a healthier diet leads to a healthier environment," said Paul Behrens, an environmental scientist at Leiden University in the Netherlands who led the work. "It's win-win."

Though the government diet recommends eating less of a particular type of food, it does not suggest eating less. The calorie count of both current and recommended diets was kept the same for the analysis. Plus, the environmental efficiency of producing different food items was also taken into account for each nation.

"In general, meat is worse than other types of food because every time something eats something else, you get a loss of energy," Behrens explained. "Eating any animal is going to have more of an impact compared to other food groups."

People living in low-income and developing countries, on the other hand, could bring about an increase in environmental stress by following recommended diets, the study found. Usually, consumption of meat, poultry and egg is low in these countries and the government wants to increase it, something that could have a negative effect on the environment.

However, that does not mean that they shouldn't shift towards healthier diets. As the study suggests, the overall effect of shifting towards government recommended diet is likely positive. Though most governments don't recognise or mention this fact, it's "another reason to shift to a healthier diet", Behrens adds.